1. Field of the Invention
The present invention relates to a device for loading and unloading sheet items such as paper containers for milk, etc. to and from main magazines in liquid charging machines.
2. Prior Art
In prior art liquid charging machines, especially liquid food charging machines, main magazines are used to continuously feed sheet items (such as gable top containers) to later processing steps. The main magazines which store the sheet items therein are provided in series so as to allow sheet items to be individually and continuously fed from the magazines.
One type of sheet item, a disposable container for liquid foodstuffs such as milk, juice, etc. which may be used, is a rectangular parallelepiped shape as shown in FIG. 8. In order to facilitate storing, transferring and handling, the container blank A is usually folded flat, as shown in FIG. 7, and then assembled into a rectangular parallelepiped shape which has a square cross section during transfer to later steps. Before filling the container with liquid foodstuff, the parapellepiped blank A' is fed onto mandrel wheels, the bottom is sealed. Then the container is filled with liquid foodstuffs by a liquid charging device.
In order to continuously transfer the flatly folded container blanks A to later steps, the main magazines are installed at the starting point of the later step. The blanks are temporarily held in the main magazine and then individually fed to the later step. When the liquid foodstuff to be filled is different in the quality and/or quantity, the container blanks must be replaced to a proper one. In this case, it is required that the blanks A' remaining in the main magazines be taken out and moved to a different location so that the proper blanks may be placed therein. When they are again to be used, the blanks A' are brought back to the main magazines.
Conventionally, such operation is not carried out automatically. There is no means provided which can take out the remaining blanks from the main magazines, resulting in great inefficiency.